Bronte illustrates the love between Catherine Linton and Heathcliff in many intense ways.  As Wuthering Heights is told through the eyes of many narrators, it demonstrates that the love between the two permeates to other characters. As children, they played together in the moors. As they grew older, Catherine and Heathcliff promised one another that they would run away together. After Edgar Linton proposes to Catherine, Catherine has a conversation with Nelly trying to decide between Heathcliff and Edgar, in which Catherine states:

“My love for Linton is like the foliage in the woods: time will change it, I’m well aware, as winter changes the trees. My love for Heathcliff resembles the eternal rocks beneath—a source of little visible delight, but necessary."

Emily Bronte constantly uses nature as a metaphor for Heathcliff, thus showing the reader how necessary he is to Catherine; how indispensable he is.

As Catherine is dying in the moors, she called out to Heathcliff to be the last one to hold her. After she does die, he cries out that he wants her ghost to haunt him for eternity. Finally, Lockwood finds the room that Catherine Linton lived in as a child with Catherine and Heathcliff written all over.